Process for the preparation of stable ionic dispersions of polyisocyanate-polyaddition products in hydroxyl containing compounds

ABSTRACT

This invention relates to a process for the preparation of finely divided, stable and relatively low viscosity dispersions of ionic polyisocyanate polyaddition products in compounds having hydroxyl groups by reacting 
     (1) organic polyisocyanate with 
     (2) compounds having primary and/or secondary amino groups and/or primary hydroxyl groups in 
     (3) compounds having at least one hydroxyl group, 
     with the proviso that compounds (3) have secondary hydroxyl groups if compounds with primary hydroxyl groups are used as compound (2), and further characterized in that at least one of the components (1) or (2) has groups which are ionic and/or capable of salt formation.

This is a continuation of application Ser. No. 16,632, filed Mar. 1,1979, now abandoned, which itself is a continuation of application Ser.No. 740,454, filed Nov. 10, 1976, now abandoned.

BACKGROUND OF THE INVENTION

Non-ionic diisocyanate polyaddition products dispersed in polyethers ofpolyesters are already known. According to the teaching of GermanAuslegeschrift No. 1,168,075, diisocyanates are reacted withbifunctional primary alcohols in a dispersing medium consisting of apolyether or polyester (molecular weight 500 to 3000) containing atleast two (exclusively secondary) hydroxyl groups in the molecule.According to German Auslegeschrift No. 1,260,142, compounds containingisocyanate and amino groups undergo a polyaddition reaction in situ in apolypropylene glycol ether dispersing agent. Non-ionic dispersions ofpolyurethanes, polyureas or polyhydrazodicarbonamides in polyvalent,higher molecular weight hydroxyl compounds obtained by the abovementioned processes are recommended as thickeners for the textile or dyeindustry because of their high viscosities even at low solids contents.

Thus a 10% (or 20%) dispersion of polyhydrazodicarbonamide in apolypropylene glycol ether obtained according to German AuslegeschriftNo. 1,260,142 for example, has a viscosity of over 10,000 (or 200,000,in the case of a 20% dispersion) cP at 25° C. This amounts to more than10 (or 200, in the case of a 20% dispersion) times the viscosity of thepure dispersing agent. When attempts are made to prepare a 40%dispersion, the reaction mixture solidifies before polyaddition has beencompleted. The high viscosities which occur at even relatively lowsolids contents seriously restrict the possibilities of using theproducts because, in many fields of application, they cannot be dosedwith the aid of the usual dosing apparatus. For producing polyurethanefoams, for example, a purpose for which such dispersions could be used,the viscosities of the starting materials must be below 2500 cP whenconventional high pressure machines are employed.

DESCRIPTION OF THE INVENTION

It has now been found that stable ionic dispersions having the desiredlow viscosity can be obtained by reacting polyisocyanates with compoundshaving salt groups or groups capable of salt formation "in situ", indispersing agents consisting of compounds containing hydroxyl groups. Inaddition to ionic compounds, other non-ionic chain-lengthening agentsmay also be used. The reaction may be carried out continuously incontinuous flow mixers, preferably in the presence of more than onepercent by weight of water, based on the total quantity of reactionmixture. Alternatively, and this is preferred because of the simplerdosing and mixing technique and in many cases the easier removal of heatof reaction, the reaction is carried out in simple stirrer apparatus(batchwise reaction in vessels) in the presence of a larger quantity ofwater, preferably more than 5% by weight, based on the total quantity ofreaction mixture.

The ability to use large amounts of water is particularly surprising forthe following reasons:

A water content of 10, 15 or 20% by weight (based on the total quantityof polyether and water), for example, increases the viscosity of apolyalkylene ether glycol at 25° C. to 4, 8 and 50 times the originalvalue, respectively (3500, 7300 and over 50,000 cP). If the watercontent is further increased, the solutions or emulsion originallyobtained in many cases separate into two phases. Both the high increasein viscosity and phase separation inevitably led experts to assume thatthe addition of water would be unsuitable for the commercial productionof low viscosity polyisocyanate polyaddition products in compoundscontaining hydroxyl groups, particularly since the water might, inaddition, interfere chemically with the isocyanate polyadditionreaction.

The present invention thus relates to a process for the in situpreparation of stable dispersions of polyisocyanate polyadditionproducts in hydroxyl containing compounds as dispersing agents by thereaction of

(1) organic polyisocyanates with

(2) compounds having primary and/or secondary amino groups and/orprimary hydroxyl groups in

(3) compounds having at least one hydroxyl group.

Compounds (3) contain secondary hydroxyl groups in cases where compounds(2) contain primary hydroxyl groups. The process is furthercharacterized in that at least one of the components (1) or (2) containsionic groups or groups capable of salt formation. The components areadvantageously reacted in the presence of more than about 1% by weight,preferably from 5 to 50% and most preferably 10 to 25% by weight ofwater, based on the total quantity of reaction mixture, the water beingsubsequently removed in known manner, if desired.

According to the invention, the compounds used as component (2) arepreferably polyamines and/or hydrazines and/or hydrazides.

In another embodiment of the invention, reactants (1) may consist inpart of (1) monoisocyanates and/or reactants (2) may consist in part ofprimary or secondary monoamines and/or monohydrazides for the purpose ofadjusting the product to a particular molecular weight. Alkanolaminesmay also be used in the polyaddition reaction for the same purpose. Inthis way, ionic polyurea or polyhydrazodicarbonamide particlescontaining reactive groups are obtained.

Although emulsifying and dispersion stabilizing substances such aspolyethers which contain amino, semicarbazide or hydrazide groups inaddition to one or two hydroxyl groups may be added if desired, theaddition of such compounds is generally not necessary since emulsifyinggroups are already built into the ionic polyaddition compounds.

The present invention also relates to stable ionic dispersions ofpolyurethane, polyureas or polyhydrazodicarbonamides in dispersingagents consisting of compounds having at least one hydroxyl group.

The ionic dispersions according to the invention may be used as startingcomponents for the production of polyurethane resins, in particularfoams.

The dispersing agents (component 3) of the present invention are thecontinuous, external phase. They are alcohols containing 2 to 8,preferably 2 to 6, most preferably 2 to 4 primary and/or secondaryhydroxyl groups and having a molecular weight of from about 62 to about16,000, preferably 62 to 12,000 and most preferably 106 to 8000. Theseinclude, for example, both low molecular weight alcohols or glycolshaving molecular weights of between 62 and about 400 which may alsocontain either, thioether or ester bonds and polyesters, polyethers,polythioethers, polyacetals, polycarbonates and polyester amides havingmolecular weights of more than 400, such as those known per se for theproduction of polyurethanes.

Suitable low molecular weight dispersing agents include monohydricalcohols such as butanol, 2-ethylhexanol, amyl alcohol and ethyleneglycol monoethyl ethers and diols or triols of the kind conventionallyused as chain lengthening agents or cross-linking agents in polyurethanechemistry, e.g., propylene glycol-(1,2) and -(1,3); butyleneglycol-(1,4) and -(2,3); hexanediol-(1,6); octanediol-(1,8); neopentylglycol; cyclohexane dimethanol (1,4-bis-hydroxymethylcyclohexane);2-methyl-1,3-propanediol; glycerol; trimethylolpropane;hexanetriol-(1,2,6); butanetriol-(1,2,4) and trimethylolethane.Particularly useful are glycols having a hydrophilic character, e.g.ethylene glycol, diethylene glycol, triethylene glycol or tetraethyleneglycol, and polyethylene glycols having a molecular weight of up to 400.In addition, however, compounds such as dipropylene glycol,polypropylene glycols having molecular weights of up to 400, dibutyleneglycol, polybutylene glycols having molecular weight of up to 400,thiodiglycol and castor oil may also be used as dispersing agentsaccording to the invention.

Also useful as dispersing agents are ester diols of the general formula

    HO--(CH.sub.2).sub.x --CO--O--(CH.sub.2).sub.y --OH and

    HO--(CH.sub.2).sub.x --O--CO--R--CO--O--(CH.sub.2).sub.x --OH

in which

R represents an alkylene or arylene group having from 1 to 10,preferably 2 to 6 carbon atoms;

x=2 to 6 and

y=3 to 5.

Examples of such compounds are δ-hydroxybutyl-ε-hydroxy-caproic acidester; ω-hydroxy-hexyl-γ-hydroxybutyric acid ester; adipicacid-bis-(β-hydroxyethyl) ester; terephthalicacid-bis(β-hydroxyethyl)-ester; and diol urethanes of the generalformula

    HO--(CH.sub.2).sub.x --O--CO--NH--R'--NH--CO--O--(CH.sub.2).sub.x --OH

in which R' represents an alkylene, cycloalkylene or arylene grouphaving from 2 to 15, preferably 2 to 6, carbon atoms and x represents aninteger of from 2 to 6, e.g.1,6-hexamethylene-bis-(β-hydroxyethylurethane) or4,4'-diphenylmethane-bis-(δ-hydroxybutylurethane).

Also suitable are diolureas of the general formula ##STR1## in which

R" represents an alkylene, cycloalkylene or arylene group having from 2to 15, preferably 2 to 9 carbon atoms,

R'41 =H or CH₃ and

x=2 or 3, e.g. 4,4'-diphenylmethane-bis-(β-hydroxyethylurea) or thecompound ##STR2##

Particularly suitable among the dihydric and trihydric low molecularweight alcohols are those which, either alone or as mixtures or with theaddition of higher molecular weight alcohols, are liquid at temperaturesbelow 50° C.

Higher molecular weight hydroxyl polyesters which are suitable asdispersing agents include, for example, reaction products of polyhydric,preferably dihydric alcohols to which trihydric alcohols may be added,and polybasic, preferably dibasic carboxylic acids. Instead of freepolycarboxylic acids, the corresponding polycarboxylic acid anhydridesor polycarboxylic acid esters of lower alcohols or mixtures thereof maybe used for preparing the polyesters. The polycarboxylic acids may bealiphatic, cycloaliphatic, aromatic and/or heterocyclic and they may besubstituted, e.g. by halogen atoms, and/or may be unsaturated. Thefollowing are mentioned as examples: Succinic acid, adipic acid, subericacid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid,trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acidanhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acidanhydride, endomethylene tetrahydrophthalic acid anhydride, glutaricacid anhydride, maleic acid, maleic acid anhydride, fumaric acid,dimeric and trimeric fatty acids such as oleic acid, optionally mixedwith monomeric fatty acids, dimethylterephthalate and bis-glycolterephthalate. Suitable polyhydric alcohols include e.g. ethyleneglycol; propylene glycol-(1,2) and -(1,3); butylene glycol-(1,4) and-(2,3); hexanediol-(1,6); octanediol-(1,8); neopentyl glycol;cyclohexane dimethanol (1,4-bis-hydroxymethyl-cyclohexane);2-methyl-1,3-propanediol; glycerol; trimethylolpropane;hexanetriol-(1,2,6); butanetriol-(1,2,4 ); trimethylolethane;triethyleneglycol; tetraethyleneglycol; polyethylene glycols;dipropylene glycol; polypropylene glycols; dibutylene glycol andpolybutylene glycols. The polyesters may also contain a proportion ofcarboxyl end groups. Polyesters of lactones, e.g. ε-caprolactam, orhydroxycarboxylic acid. e.g. ω-hydroxycaproic acid may also be used.

The higher molecular weight polyethers preferably used as dispersingagents according to the invention are obtained in known manner byreaction of starting compounds which contain reactive hydrogen atomswith alkylene oxides such as ethylene oxide, propylene oxide, butyleneoxide, styrene oxide, tetrahydrofuran or epichlorohydrin or with anymixtures of these alkylene oxides. In many cases it is preferred to usepolyethers which contain predominantly primary hydroxyl groups. Suitablestarting compounds containing reactive hydrogen atom include e.g. water,methanol, ethanol, ethylene glycol, propylene glycol-(1,2) or -(1,3),butylene glycol-(1,4) or -(2,3), hexanediol-(1,6), octane diol-(1,8),neopentyl glycol, 1,4-bis-hydroxymethylcyclohexane,2-methyl-1,3-propanediol, glycerol, trimethylolpropane, hexanetriol-(1,2,6), butanetriol-(1,2,4), trimethylolethane, pentaerythritol,mannitol, sorbitol, methylglycoside, sucrose, phenol isononylphenol,resorcinol, hydroquinone, 1,2,2- or 1,1,3-tris-(hydroxyphenyl)-ethane,ammonia, methylamine, ethylenediamine, tetra- or hexamethylenediamine,diethylenetriamine, ethanolamine, diethanolamine, triethanolamine,aniline, phenylenediamine, 2,4- and 2,6-diaminotoluene andpolyphenylpolymethylene-polyamines of the kind obtained byaniline-formaldehyde condensation. Resinous materials such as phenol andresol resins may also be used as starting materials. Polyethers modifiedby vinyl polymers are also suitable for the process according to theinvention. Products of this kind may be obtained by polymerizing e.g.styrene and acrylonitrile in the presence of polyethers (U.S. Pat. Nos.3,383,351, 3,304,273, 3,523,095, 3,110,695, German Pat. No. 1,152,536).

Among the polythioethers which should be particularly mentioned are thecondensation products obtained from thiodiglycol on its own and/or withother glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acidsor amino alcohols. The products obtained are either polythio mixedethers, polythioether esters or polythioether ester amides, depending onthe components.

Suitable polyacetals include e.g. the compounds which can be preparedfrom glycols such as diethylene glycol, triethylene glycol,4,4'-dioxethoxy-diphenyldimethylmethane, hexanediol and formaldehyde.Polyacetals suitable for the purpose of the invention may also beprepared by the polymerization of cyclic acetals.

Suitable polycarbonates containing hydroxyl groups include these knownper se such as the products obtained from the reaction of diols such aspropanediol-(1,3), butane-diol (1,4) and/or hexanediol-(1,6), diethyleneglycol, triethylene glycol or tetraethylene glycol withdiaryl-carbonates, e.g. diphenylcarbonate or phosgene.

Suitable polyester amides and polyamides include, for example, thepredominantly linear condensates obtained from polyvalent saturated andunsaturated carboxylic acids or their anhydrides and polyvalentsaturated and unsaturated amino alcohols, diamines, polyamines ormixtures thereof.

Mixtures of the above mentioned high and low molecular weight dispersingagents may of course also be used according to the invention, as alreadymentioned above.

The dispersing agents which are preferred according to the invention arethose which are free from amy labile groups, e.g. ester groups, whichare liable to be destroyed by hydrolysis or aminolysis in the process ofthe present invention. Unstable compounds of this kind are preferablyadded to the finished dispersion only after completion of thepolyaddition reaction.

The hydroxyl compounds and mixtures thereof used as dispersing agentsaccording to the invention should be chosen so that when mixed with thewater to be added according to the invention and with any hydroxylcompounds or, preferably, amino compounds and optionally inert solvents,they are liquid at the reaction temperature, i.e. in the form ofsolutions or emulsions. Their viscosity at the reaction temperatureshould generally be below 20,000 cP and preferably below 5000 cP so thatconventional stirrer and mixing apparatus can be employed.

If inert solvents are to be used, they should preferably distill off asazeotropic mixtures with water. Examples include benzene and toluene.

The following compounds or mixtures thereof may be used in the processaccording to the invention as components and contain (a) (i) at leastone hydrogen atom reactive with isocyanate groups or (a) (ii) at leastone isocyanate group and (b) at least one ionic group or group capableof salt formation:

(I) Compounds containing basic amino groups capable of being neutralizedwith aqueous acids or tertiary amino groups capable of beingquaternized:

(a) Alcohols,

in particular alkoxylated aliphatic, cycloaliphatic aromatic andheterocyclic secondary amines, e.g. N,N-dimethylethanolamine;N,N-diethylethanolamine; N,N-dibutylethanolamine;1-dimethylamino-propanol-(2); N,N-methyl-β-hydroxyethylaniline;N,N-methyl-β-hydroxypropylaniline; N,N-ethyl-β-hydroxyethylaniline;N,N-butyl-β-hydroxyethylaniline; N-oxethylpiperidine;N-oxethylmorpholine; α-hydroxyethylpyridine and γ-hydroxyethylquinoline.

(b) diols and triols,

in particular alkoxylated aliphatic, cycloaliphatic, aromatic andheterocyclic primary amines, e.g. N-methyl-diethanolamine;N-butyl-diethanolamine; N-oleyl-diethanolamine;N-cyclohexyl-diethanolamine; N-methyl-diisopropanolamine;N-cyclohexyl-diisopropanolamine; N,N-dioxethylaniline;N,N-dioxyethyl-m-toluidine; N,N-dioxethyl-p-toluidine;N,N-dioxypropyl-napthylamine; N,N-tetraoxyethyl-α-aminopyridine;dioxyethylpiperazine; polyethoxylated butyl diethanolamine;polypropoxylated methyl diethanolamine (molecular weight about 1000);polypropoxylated methyldiethanolamine (molecular weight about 2000);polyesters having tertiary amino groups;tri-[2-hydroxypropyl-(1)]-amine; N,N-di-n-(2,3-dihydroxypropyl)-aniline;N,N'-dimethyl-N,N'-bis-oxethylhydrazine andN,N'-dimethyl-N,N'-bis-oxypropyl-ethylenediamine.

(c) Amino alcohols,

e.g. products of addition of alkylene oxide and acrylonitrile to primaryamines, which addition products are obtained by hydrogenation. Theseinclude, for example N-methyl-N-(3-aminopropyl)-ethanolamine;N-cyclohexyl-N-(3-aminopropyl)-propanol-(2)-amine;N,N-bis-(3-aminopropyl-ethanolamine and N-3-aminopropyl-diethanolamine.

(d) Amines,

e.g. N,N-dimethylhydrazine; N,N-dimethyl-ethylenediamine;1-di-ethylamino-4-amino-pentane; α-aminopyridine;3-amino-N-ethylcarbazole; N,N-dimethyl-propylene-diamine;N-aminopropyl-piperidine; N-amino-propyl-morpholine;N-amino-propyl-ethyleneimine and 1,3-bis-piperidino-2-aminopropane.

(e) Diamines, triamines, amides

in particular those obtained by hydrogenation of products of theaddition of acrylonitrile to primary or disecondary amines, e.g.bis-(3-aminopropyl)-methylamine; bis-(3-aminopropyl)-cyclohexylamine;bis-(3-aminopropyl)-aniline; bis-(3-aminopropyl)-toluidine;diaminocarbazole; bis-(aminopropoxyethyl)-butylamine;tris-(aminopropyl)-amine; orN,N'-bis-carbonamidopropyl-hexamethylenediamine; and the compoundsobtained by the addition of acrylamide to diamine or diols.

(II) Compounds containing halogen atoms which are capable ofquaternizing reactions or the corresponding esters of strong acids:

2-Chloroethanol; 2-bromoethanol; 4-chlorobutanol; 3-bromopropanol;β-chloroethylamine; 6-chlorohexylamine; ethanolamine-sulphuric acidester; N,N-bis-hydroxyethyl-N'-m-chloromethylphenylurea;N-hydroxyethyl-N'-chlorohexylurea; glycerol amino-chloroethyl-urethane;chloroacetyl-ethylenediamine; bromoacetyl-dipropylene-triamine;trichloroacetyl-triethylenetetramine; glycerol-α-bromohydrin;polypropoxylated glycerol-α-chlorohydrin; polyesters containingaliphatically bound halogen or 1,3-dichloropropanol-2.

The following are mentioned as corresponding isocyanates:Chlorohexylisocyanate; m-chlorophenyl-isocyanate;p-chlorophenylisocyanate; bis-chloromethyl-diphenylmethane-diisocyanate;2,4-diisocyanato-benzyl chloride; 2,6-diisocyanatobenzyl chloride;N-(4-methyl-3-isocyanatophenyl)-β-bromoethyl-urethane.

(III) Compounds containing carboxylic acid or hydroxyl groups capable ofsalt formation:

(a) Hydroxy and mercapto carboxylic acids: Glycollic acid, thioglycollicacid, lactic acid, trichlorolactic acid, malic acid, dihydroxymaleicacid, dihydroxyfumaric acid, tartaric acid, dihydroxytartaric acid,mucic acid, saccharic acid, citric acid, glyceroboric acid,pentaerythrito-boric acid, mannitoboric acid, salicyclic acid,2,6-dihydroxybenzoic acid, protocatechuic acid, α-resorcyclic acid,β-resorcyclic acid, hydroquinone-2,5-dicarboxylic acid,4-hydroxyisophthalic acid, 4,6-dihydroxy-isophthalic acid,hydroxyterephthalic acid, 5,6,7,8-tetrahydronaphthol-(2)-carboxylicacid-(3), 1-hydroxynaphthoic acid-(2), 2,8-dihydroxynaphthoic acid-(3),β-hydroxypropionic acid, m-hydroxybenzoic acid, pyrazolone carboxylicacid, uric acid, barbituric acid, resols and other formaldehyde-phenolcondensation products.

(b) Polycarboxylic acids:

Sulphodiacetic acid, nitrilotriacetic acid, ethylenediaminotetraceticacid, diglycollic acid, thiodiglycollic acid,methylene-bis-thioglycollic acid, malonic acid, oxalic acid, succinicacid, glutaric acid, adipic acid, maleic acid, fumaric acid, gallicacid, phthalic acid, tetrachlorophthalic acid, isophthalic acid,terephthalic acid, naphthalene tetracarboxylic acid-(1,4,5,8),o-tolyl-imido-diacetic acid, β-naphthylimido-diacetic acid, pyridinedicarboxylic acid, dithiodipropionic acid.

(c) Aminocarboxylic acids:

Oxaluric acid; anilinoacetic acid; 2-hydroxy-carbazolecarboxylicacid-(3); glycine; sarcosine; methionine; α-alanine; β-alanine;6-aminocaproic acid; 6-benzoylamino-2-chlorocaprioc acid;4-amino-butyric acid; aspartic acid; glutamic acid; histidine;anthranilic acid; 2-ethylaminobenzoic acid;N-(2-carboxyphenyl)-aminoacetic acid;2-(3'-amino-benzenesulphonylamino)-benzoic acid; 3-aminobenzoic acid;4-aminobenzoic acid; N-phenylamino-acetic acid; 3,4-diaminobenzoic acid;5-aminobenzenedicarboxylic acid; 5-(4'-aminobenzoylamino)-2-aminobenzoicacid.

(d) Hydroxy and carboxy sulphonic acids:

2-Hydroxyethane sulphonic acid; phenolsulphonic acid-(2);phenolsulphonic acid-(3); phenolsulphonic acid-(4); phenoldisulphonicacid (2,4); sulphoacetic acid; m-sulphobenzoic acid; p-sulphobenzoicacid; benzoic acid-(1)-disulphonic acid-(3,5); 2-chloro-benzoicacid-(1)-sulphonic acid-(4); 2-hydroxy-benzoic acid-(1)-sulphonicacid-(5); naphthol-(1)-sulphonic acid; naphthol-(1)-disulphonic acid;8-chloronaphthol-(1)-disulphonic acid; naphthol-(1)-trisulphonic acid;naphthol-(2)-sulphonic acid-(1); naphthol-(2)-trissulphonic acid;1,7-dihydroxy-naphthalenesulphonic acid-(3);1,8-dihydroxy-naphthalene-disulphonic acid-(2,4); chromotropic acid;2-hydroxynaphthotic acid-(3)-sulphonic acid-(6);2-hydroxy-carbazole-sulphonic acid-(7).

(c) Aminosulphonic acids:

Amidosulphonic acid; hydroxylamine monosulphonic acid; hydrazinedisulphonic acid; sulphanilic acid; N-phenylamino-methanesulphonic acid;4,6-dichloroanilinesulphonic acid-(2); phenylenediamine-(1,3)-disulphonic acid-(4,6);N-acetyl-naphthyl-amine(1)-sulphonic acid-(3);naphthylamine-(1)-sulphonic acid; naphthylamine-(2)-sulphonic acid;naphthylaminedisulphonic acid; naphthylamine-trisulphonic acid;4,4'-di-(p-aminobenzoylamino)-diphenylurea-disulphonic acid-(3,3');phenylhydrazine-disulphonic acid-(2,5);2,3-dimethyl-4-aminoazo-benzene-disulphonic acid-(4'-5);4'-aminostilbene-disulphonic acid-(2,2')-4-azo-4-anisole;carbazoledisulphonic acid-(2,7); taurine; methyltaurine; butyltaurine;3-amino-benzoic acid-(1)-sulphonic acid-(5);3-amino-toluene-N-methane-sulphonic acid;6-nitro-1,3-dimethylbenzene-4-sulphamic acid;4,6-diaminobenzenedisulphonic acid-(1,3); 2,4-diaminotoluene-sulphonicacid-(5); 4,4'-diaminodiphenyl-disulphonic acid-(2,2');2-aminophenol-sulphonic acid-(4); 4,4'-diamino-diphenylether-sulphonicacid(2); 2-aminoanisole-N-methanesulphonic acid;2-amino-diphenylamine-sulphonic acid.

Salt forming agents for Group I may be inorganic or organic acids,compounds containing reactive halogen atoms, or the corresponding estersof strong acids. The following are some examples of such compounds:

Hydrochloric acid, nitric acid, hypophosphorous acid, amidosulphonicacid, hydroxylamine monosulphonic acid, formic acid, acetic acid,glycollic acid, lactic acid, chloroacetic acid, ethyl bromoacetate,sorbitoboric acid, methyl chloride, butyl bromide, dimethylsulphate,diethylsulphate, benzyl chloride, p-toluene-sulphonic acid methyl ester,methyl bromide, ethylene chlorohydrin, ethylene bromohydrin,glycero-α-bromohydrin, ethyl chloroacetate, chloroacetamide,bromoacetamide, dibromoethane, chlorobromobutane, dibromobutane,ethylene oxide, propylene oxide and 2,3-epoxypropanol.

The compounds of Group II may be quaternized or quaternized withtertiary amines or also with sulphides or phosphines to producequaternary ammonium and phosphonium salts and ternary sulphonium salts.

Examples include trimethylamine, triethylamine, tributylamine, pyridine,triethanolamine, the compounds mentioned under Groups Ia and Ib,dimethylsulphide, diethylsulphide, thiodiglycol, thiodiglycollic acid,trialkylphosphines, alkylarylphosphines and triarylphosphines.

The agents used to form salts with compounds of Group III may beinorganic or organic bases such as sodium hydroxide, potassiumhydroxide, potassium carbonate, sodium bicarbonate, ammonia or primary,secondary or tertiary amines. Organic phosphorus compounds may also beused as compounds capable of salt formation. These phosphorus compoundsinclude those basic phosphines which can be built into the molecule,e.g. diethyl-β-hydroxyethyl phosphine,methyl-bis-β-hydroxyethylphosphine or tris-β-hydroxymethylphosphine andderivatives, e.g. phosphinic acids, phosphonous acids, phosphonic acidsand esters of phosphorous and phosphoric acid and their thioanalogues,e.g. bis-(α-hydroxy-isopropyl)-phosphinic acid, hydroxyalkane phosphonicacid and phosphoric acid-bis-glycol ester.

According to the invention, it is preferred to use ionogenic componentscarrying sulphonate, carboxylate and/or ammonium groups.

For preparing anionic polyol dispersions, ionification of the productsof the process is most simply carried out by reacting salts, for examplesulphonates or carboxylates containing groups which are reactive withisocyanates, with polyisocyanates in the polyol. The salts may either beadded in the form of dilute aqueous solutions or the pure salts may bedissolved in the polyol by the addition of water. Alternatively, thefree acid may be mixed with the polyol, and aqueous alkali may then bestirred in until the reaction mixture is neutral.

Cationic dispersions, for example products containing quaternarynitrogen, may be prepared, for example, by first preparing apolyioscyanate polyaddition product containing tertiary nitrogen in thepolyol by the methods to be described hereinafter, and then distillingoff the water completely, and then methylating, for example with anequivalent or subequivalent quantity of dimethylsulphate. Instead ofusing organic alkylating agents, cationic groups may also besubsequently formed by means of organic acids or mineral acids,optionally in the presence of water.

In some cases it may be advantageous to use the ionogenic component inthe form of a prepolymer. For example, a hydroxyl compound containingionic groups or groups capable of salt formation may first be reactedwith an excess of polyisocyanate and the resulting ionogenic prepolymermay then be used as the isocyanate component to which non-ionogenicisocyanates may be added in the process according to the invention.Conversely, ionogenic isocyanates may, of course, first be reacted withan excess of a polyamine and then used according to the invention.

The total quantity of ionogenic components (i.e. salts or salt formingcomponents) is such that the finished polyurethane or polyureadispersion has an ionic group content of from 0.001 to about 0.5,preferably from 0.01 to 0.25 equivalents per 100 g of solid matter.

If the salt forming compounds or compounds containing salt groups are atleast bifunctional, they may be used as the sole component (1) or (2) inthe process according to the invention for preparing the ionicdispersion.

If, on the other hand, the components which contain salt groups or arecapable of salt formation are only monofunctional, theirmonofunctionality should be compensated by the addition of componentshaving a functionality higher than 2 in order to obtain higher molecularweights.

The other components suitable for preparation of the dispersionsaccording to the invention, which are reactive towards isocyanates butwhich are free from ionic groups, are particularly polyamines,hydrazines and hydrazides.

Suitable polyamines include divalent and/or higher valent primary and/orsecondary aliphatic, araliphatic, cycloaliphatic and aromatic amines,e.g. ethylene diamine, 1,2- and 1,3-propylene diamine;tetramethylenediamine; hexamethylenediamine, dodecamethylenediamine;trimethyldiaminohexane; N,N'-dimethyl-ethylenediamine;2,2'-bis-aminopropylmethylamine; higher homologues of ethylene diaminesuch as diethylene triamine, triethylene tetramine and tetraethylenepentamine; homologues of propylenediamine such as dipropylenetriamine;piperazine; N,N'-bis-aminoethylpiperazine; triazine; 4-aminobenzylamine;4-aminophenylethylamine;1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane;4,4'-diaminodicyclohexylmethane and propane; 1,4-diaminocyclohexane;phenylenediamines; naphthylenediamines; condensates of aniline andformaldehyde; tolylenediamines; bis-amino-methylbenzenes and derivativesof the above mentioned aromatic amines monoalkylated on one or bothnitrogen atoms. The polyamines generally have a molecular weight of from60 to about 10,000, preferably 60 to 3000 and most preferably 60 to1000.

Suitable hydrazines include hydrazine itself and monosubstituted orN,N'-disubstituted hydrazines in which the substituents may be C₁ to C₆alkyl groups, cyclohexyl groups or phenyl groups. The hydrazinesgenerally have a molecular weight of from 32 to about 500. Hydrazineitself is preferred.

Suitable hydrazides include the hydrazides of dibasic or higher basiccarboxylic acids such as carbonic acid; oxalic acid; malonic acid;succinic acid; adipic acid; sebacic acid; azelaic acid; maleic acid;furmaric acid; phthalic acid; isophthalic acid; terephthalic acid;esters of hydrazine monocarboxylic acid with dihydric or higher hydricalcohols and phenols such as ethanediol, propanediol-(1,2),butanediol-(1,2), -(1,3) and -(1,4), hexanediol, diethyleneglycol,triethyleneglycol, tetraethyleneglycol, dipropyleneglycol,tripropyleneglycol and hydroquinone; and amides or hydrazinemonocarboxylic acid (semicarbazides), for example with the abovementioned diamines and polyamines. The hydrazides generally have amolecular weight of from 90 to about 10,000, preferably 90 to 3000 andmost preferably 90 to 1000.

The amines and hydrazines mentioned above may be used in the form oftheir dilute aqueous solutions or they may be used as mixtures with thedispersing agent diluted with the required quantity of water.

The starting components (1) used according to the invention also includealiphatic, cycloaliphatic, araliphatic, aromatic and heterocyclicpolyisocyanates such as those described, for example, by W. Siefken inJustus Liebigs Annalan der Chemie, 562, pages 75 to 136. These includeethylene diisocyanate; 1,4-tetramethylene diisocyanate;1,6-hexamethylene diisocyanate; 1,12-dodecane-diisocyanate;cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and -1,4-diisocyanate andany mixtures of these isomers;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane as describedin German Auslegeschrift No. 1,202,785 and U.S. Pat. No. 3,401,190; 2,4-and 2,6-hexahydrotolylene diisocyanate and any mixtures of theseisomers; hexahydro-1,3 and/or -1,4-phenylene diisocyanate;perhydro-2,4'- and/or 4,4'-diphenylmethane diisocyanate; 1,3- and1,4-phenylenediisocyanate; 2,4- and 2,6-tolylene diisocyanate and anymixtures of these isomers; diphenylmethane-2,4'- and/or4,4'-diisocyanate; naphthylene-1,5-diisocyanate;triphenylmethane-4,4',4"-triisocyanate; polyphenyl-polymethylenepolyisocyanates of the kind which can be obtained by anilineformaldehyde condensation followed by phosgenation and which have beendescribed, for example, in British Pat. Nos. 874,430 and 848,671; m- andp-isocyanatophenyl-sulphonyl-isocyanates according to U.S. Pat. No.3,454,606; perchlorinated aryl polyisocyanates such as those describede.g. in German Auslegeschrift No. 1,157,601 and U.S. Pat. No. 3,277,138;polyisocyanates containing carbodiimide groups as described in GermanPat. No. 1,092,007 and U.S. Pat. No. 3,152,162; diisocyanates of thekind described in U.S. Pat. No. 3,492,330; polyisocyanates havingallophanate groups as described e.g. in British Pat. No. 994,890;Belgian Pat. No. 761,626 and published Dutch Patent Application No.7,102,524; polyisocyanates having isocyanurate groups as described e.g.in U.S. Pat. No. 3,001,973; German Pat. Nos. 1,022,789, 1,222,067 and1,027,394 and German Offenlegungsschriften Nos. 1,929,034 and 2,004,048;polyisocyanates with urethane groups, e.g. as described in Belgian Pat.No. 752,261 and U.S. Pat. No. 3,394,164; polyisocyanates having acylatedurea groups according to German Pat. No. 1,230,778; polyisocyanates withbiuret groups as described e.g. in German Pat. No. 1,101,394; U.S. Pat.Nos. 3,124,605 and 3,201,372; and British Pat. No. 889,050;polyisocyanates prepared by telomerization reactions as described inU.S. Pat. No. 3,654,106; polyisocyanates with ester groups, for examplethose mentioned in British Pat. Nos. 965,474 and 1,072,956; U.S. Pat.No. 3,567,763 and German Pat. No. 1,231,688; reaction products of theabove mentioned isocyanates with acetals according to German Pat. No.1,072,385 and polyisocyanates containing polymeric fatty acid groupsaccording to U.S. Pat. No. 3,455,883.

The distillation residues containing isocyanate groups obtained from thecommercial production of isocyanates may also be used, if desired assolutions in one or more of the above mentioned polyisocyanates. Anymixtures of the above mentioned polyisocyanates may also be used.

So-called prepolymers may, of course, also be used as isocyanatecomponents according to the invention i.e. reaction products of lowmolecular weight and/or higher molecular weight compounds havinghydroxyl and/or amino groups, e.g. those of the kind mentioned above,with an excess of the monomeric polyisocyanates described above.

Some or all of the isocyanates or amines, hydrazines or hydrazides usedin the present process according to the invention may have afunctionality higher than 2. It must be regarded as surprising that thereaction according to the invention of such higher functional compoundsin dispersing agents which have hydroxyl groups does not result in solidor, at least, very highly viscous reaction products but rather givesrise to finely divided, low viscosity dispersions.

The polyaddition products produced by the present process as dispersionsin compounds containing hydroxyl groups may, as already mentioned above,be modified by the addition of a proportion of ionogenic butmonofunctional isocyanates, amines, hydrazine derivatives or ammonia towhich non-ionogenic compounds may also be added.

Thus, for example, the average molecular weight of polyaddition productscan be adjusted as desired by the incorporation of such monofunctionalcompounds. Polyureas or polyurea polyhydrazodicarbonamides containingfree hydroxyl groups can be obtained by using alkanolamines havingprimary or secondary amino groups. The introduction of other groups suchas ester groups, longer aliphatic groups, tertiary amino groups andactive double bonds, can also be achieved by the addition of suitablysubstituted monoamines, diamines or isocyanates.

Suitable non-ionogenic monofunctional isocyanates include e.g. alkylisocyanates such as methyl, ethyl, isopropyl, isobutyl, hexyl, lauryland stearyl isocyanate; cyclohexyl isocyanate; cyclohexyl isocyanate;phenyl isocyanate; tolyl isocyanate; 4-chlorophenylisocyanate anddiisopropylphenylisocyanate.

Suitable non-ionogenic monoamines include e.g. alkylamines anddialkylamines containing C₁ to C₁₈ alkyl groups; cycloaliphatic aminessuch as cyclohexylamine and its homologues; aniline and N-alkylanilinesand aniline derivatives which are substituted in the benzene ring;alkanolamines such as ethanolamine, diethanolamine, propanolamine,dipropanolamine, butanolamine and dibutanolamine and diamines having atertiary and primary or secondary amino groups, e.g.N,N-dimethyl-ethylenediamine and N-methylpiperazine. Suitablemonofunctional hydrazine derivatives and hydrazides include e.g.,N,N-dialkylhydrazines, the hydrazides of monocarboxylic acids, hydrazinemonocarboxylic acid esters of monofunctional alcohols or phenols, andsemicarbazides e.g. methyl, ethyl, propyl, butyl, hexyl, dodecyl,stearyl, phenyl and cyclohexylsemicarbazide.

The molecular weight of the polyaddition products prepared according tothe invention as dispersions in hydroxyl compounds is determined by theproportion by weight of polyamine, hydrazine or hydrazide on the onehand to polyisocyanate and monofunctional compounds, if added, on theother. It is particularly preferred to react approximately equivalentquantities of isocyanates and hydroxyl functional or, preferably, aminofunctional compounds in the hydroxyl containing dispersing agent. Chainlengthening agents which have primary hydroxyl groups are reacted in adispersing agent containing exclusively secondary hydroxyl groups. Alimited excess of isocyanate may also be used but the products thenobtained have a relatively high viscosity, increasing with the amount ofisocyanate excess used, since the excess of polyisocyanate reacts withthe dispersing agent. Low molecular weight chain lengthening agents suchas amine, hydrazine or hydrazide, on the other hand, may be used inlarge excess without causing an increase in the viscosity; polyadditionproducts having reactive end groups and a limited molecular weight areobtained in such cases. The equivalent ratio of polyisocyanate to chainlengthening agent is generally kept between about 0.50 and about 1.50and preferably between 0.90 and 1.10. It is particularly preferred touse approximately equivalent quantities.

When polyisocyanates are reacted with polyamines or hydrazines orhydrazides in the presence of compounds having hydroxyl groups, theisocyanate groups react very preferentially with the amino groups but acertain proportion of the hydroxyl groups of the dispersing agent alsotake part in the reaction, depending on the reaction conditions. Thisreaction gives rise to polyurea and/or polyhydrazodicarbonamide chainswhich are chemically linked with the monohydric, or preferably,polyhydric alcohol used as dispersing agent. Such end groups presumablyhave a dispersing action on the solid particles. The extent to which thehydroxyl groups take part in the polyaddition reaction dependsparticularly on the reaction temperatures and on the water content. Iftoo large a number of higher molecular weight polyol molecules reactwith the polyisocyanates, highly viscous dispersions are obtained. Thisobviously occurs in the process according to German Auslegeschrift No.1,260,142. On the other hand, if the proportion of polyol moleculestaking part in the reaction is too low, that part of the resultingdispersions which is composed of the larger particles is liable to beunstable and undergo sedimentation. The process according to theinvention which comprises reaction in a simple stirrer apparatus withreflux condenser when large quantities of water are used or incontinuous flow mixers when smaller quantities of water are used, hasthe surprising effect of making it possible for the proportion of theNCO/OH reaction to be adjusted so that finely divided dispersions havingthe required low viscosity are obtained, but at the same time, coarserparts of the dispersion are still sufficiently stable so that they willnot undergo sedimentation even during prolonged storage at elevatedtemperatures.

If, however, the ionic content is very low, it is advisable to includeemulsifying substances in the polyaddition reaction to increase thestability of the dispersion. These emulsifiying substances include e.g.linear polyethers having an average molecular weight of about 300 toabout 4000 and carrying isocyanate groups or amino or hydrazide groupsat both ends of the chain or, preferably, at only one end.

Thus, for example, minor quantities of isocyanate adducts of diolshaving the following general formula ##STR3## may be used as emulsifyingagents. In the above formula, R represents a divalent group such as canbe obtained by removal of the isocyanate groups from a diisocyanatehaving a molecular weight of from about 112 to about 1000; X representsoxygen or --NR"--, R' and R", which may be the same or different,represent monovalent hydrocarbon groups having from 1 to 12 carbonatoms, R'" represents hydrogen or a monovalent hydrocarbon group havingfrom 1 to 8 carbon atoms and n represents an integer of from 4 to 89.

The preparation of such hydrophilic diols has been described, forexample, in German Offenlegungsschrift No. 2,314,512.

Modified polyethers acting as dispersing agents which may be usedaccording to the invention include not only those having the abovegeneral formula but also, for example, addition products of excessdiisocyanates and/or polyisocyanates of the kind mentioned above asexamples with monofunctional and/or bifunctional hydroxyl polyethershaving an average molecular weight of from 300 to 4000, which may befreed from unreacted free isocyanate by thin layer evaporation. Ifdesired, these isocyanate prepolymers may also be reacted with excessfree isocyanate to form allophanate isocyanates. Addition productscontaining isocyanate end groups may also be converted into polyetherscontaining amino or semicarbazide end groups by reaction with excessdiamines or hydrazine, e.g. according to German Auslegeschrifts Nos.1,122,254 or 1,138,200.

Polyethers containing amino end groups, e.g. those prepared by theprocess according to U.S. Pat. No. 3,155,278 or German AuslegeschriftNo. 1,215,373 may also be used as dispersing agents according to theinvention.

Lastly, hydroxyl polyethers may be reacted with phosgene to convert theminto chloroformic acid esters which may then be reacted with excessdiamine or hydrazine. As already mentioned above, polyethers which carryan isocyanate or amino group at only one chain end are preferred asdispersing agents.

The modified polyethers which have a dispersing action are generallyonly added in quantities of up to about 15% by weight, preferably up to3% by weight (based on the total quantity of polyol and solid content)to the particularly preferred dispersions according to the inventionwhich have a solids content of about 10 to about 60% by weight. If thedispersions have a higher or lower solids content, a correspondinglarger or smaller quantity of dispersing agent is used.

According to a less preferred variation of the process of the invention,compounds of the type mentioned above having two or more primaryhydroxyl groups and a molecular weight of from about 62 to about 400 maybe reacted with polyisocyanates to which primary alcohols may be addedto produce polyurethane dispersions. In that case, however, it should benoted that only dispersing agents which contain exclusively secondaryhydroxyl groups may be used and they should preferably have a molecularweight of more than about 500 in order to ensure selective reaction ofthe polyisocyanate with the primary hydroxyl compounds.

The quantity of water which, according to the preferred embodiment ofthe invention, may be present during the polyaddition reaction is ofdecisive importance in determining salt formation, particle size,particle size distribution and the final viscosity of the dispersion.Several factors must be taken into account simultaneously: (1) theviscosity and hydrophilic or hydrophobic character of the dispersingagent containing alcoholic groups; (2) the solubility or emulsifiabilityof the starting components used for the isocyanate polyadditionreaction; and (3) the ionic content and solids content of the resultingdispersion and the temperatures employed. The sequence and method ofaddition may also be of some influence. With increasing water content, asignificant increase in viscosity occurs, particularly if the dispersingagent used is only slightly hydrophilic and ionic content is low, asalready mentioned above by way of example. In all cases, it is necessaryto ensure that the reaction mixture can be vigorously mixed in thepresence of water during the polyaddition reaction and during thesubsequent removal of water by distillation. The quantity of water addedwould generally be less than 50% by weight but should be at least 2% byweight, based on the total quantity of the reaction mixture. The higherthe desired solids content of the dispersion, the more water should beadded. The optimum quantity of water is that which results in the lowestpossible final viscosity of the dispersion prepared according to theinvention but which does not require the removal of unnecessarily largequantities of water by distillation. The preferred quantity of water is,in many cases, between about 5 and about 25% by weight based on thereaction mixture.

When very large quantities of water are used, the ionic group contentprevents separation of the phases of the reaction mixture during thepolyaddition reaction or solidification during the removal of the waterby distillation. It is therefore possible to use a much higher solidcontent than in the case of non-ionic products. If very hydrophilicalcohols are used, it is also permissible to use small quantities ofwater, i.e. about 1% by weight.

For obtaining a very low final viscosity, it is advantageous to employ avery high reaction temperature from the start of the polyadditionreaction, preferably a temperature close to the boiling point of water.

When using stirrer vessels with reflux condensers, the heat produced inthe strongly exothermic isocyanate reaction can easily be removed byboiling under reflux. At the same time, any adducts formed in thegaseous phase above the liquid reaction mixture can be continuouslywashed into the liquid phase by the water while still in statu nascendiand finely dispersed therein.

It has been found that in some cases when low molecular weightdispersing agents and where substantially linear polyisocyanate additioncompounds are used, solutions rather than dispersions are formed. Inthis context, "solutions" means a clear, uniform and homogeneous mixtureof polyaddition product and dispersing agent. Such solutions are notintended to be covered by the term "dispersion" as used throughout thespecification. It has been found, however, that formation of a solutioncan be easily avoided by the presence of small amounts of water in thedispersing agent. Generally an amount of water of about 1% by weight,based on the total weight of the dispersion is sufficient to avoid theformation of a solution. However, as set forth below, the amount ofwater in the dispersions may be varied within wide limits depending onthe particular system involved and the intended use. In most cases,however, the dispersions may be made completely water-free without beingundesirably converted into solutions.

Various methods may be employed for mixing the dispersing agent with thereactants. In the simplest case, the hydroxyl containing dispersingagent, the desired quantity of water and the amino or primary hydroxylcompound are introduced into a stirrer vessel and heated with stirring,for example to 70° to 90° C., and the isocyanate component is addedrapidly so that the reaction mixture boils vigorously under reflux. Whenproducing dispersions with a high solids content, it is advantageous tointroduce the polysocyanate or polyisocyanate mixture into the lowerthird of the liquid in the reaction vessel. If suitable stirrerapparatus are employed, the reaction temperature may be raised to 105°to 115° C. by employing a slight excess pressure. When the isocyanategroups have undergone complete reaction, the water and any inert solventpresent are distilled off at reduced pressure and the dispersiondischarged through a sieve. In many cases, the (aqueous) solution ofamino compounds and polyisocyanate may, of course, be introducedsimultaneously into the dilution of dispersing agent in water. In thatcase, however, any excess of isocyanate should be avoided. Part of theheat of reaction may be used up by, for example, mixing thepolyisocyanates with part of the alcohol used as dispersing agent atroom temperature immediately before it is added to the reaction mixture.If the process according to the invention is desired to be carried outcontinuously, for example in the case of a large scale commercialproduction of more than 1000 tons per month, the dispersing agent,reactants and optionally water may be continuously fed into continuousflow mixers. In view of the strongly exothermic nature of the reaction,which increases with increasing solid content, and hence the increasingvapor pressure, the time of stay in the reactor must be so short thatthe reaction temperature in the premixer as far as possible does notexceed 100° C. When preparing a 40% dispersion, for example, the timerequired for the flow through the mixer should not be substantiallyabove 1 to 3 seconds. The premixed reactants are then introduced into afinal stirrer vessel in which they stay for 20 to 30 minutes beforebeing forced into another vessel or removal of the water bydistillation. It is advisable to use less water when carrying out thecontinuous flow mixing process than that used for the discontinuousreaction under reflux.

Distillation of water may also be carried out at a later stage, but thedispersions then obtained have a higher viscosity.

In practice, for obtaining very low viscosities, preference will begiven to the discontinuous process in reaction vessels followed byimmediate removal of water by distillation because of its greatsimplicity, reliability in reaction control and reproducibility.

The quantity of water required for subsequent reactions such aspreparation of polyurethane foams may, of course, be left in thefinished dispersion.

The concentration of polyaddition products in the dispersing agentcontaining hydroxyl groups may vary within a wide range but is generallybetween about 1 and about 75% by weight, particularly between 5 and 65%by weight. The dispersions prepared according to the invention haveviscosities of up to 80,000 cP, preferably up to 40,000 cP, at 25° C.,depending on their concentration. After dilution to a solids content of10% by weight, they generally have a viscosity below 2500, preferablybelow 1500 cP at 25° C. It is surprisingly found that if dispersions areprepared at very high concentrations and diluted to the desired finalconcentration, the products obtained have a lower viscosity than thosedirectly prepared with the desired solids content.

As already explained above, dispersions having a surprisingly highsolids content, up to 60% or more, can be prepared economically instirrer vessels with reflux condenser in spite of the strongelyexothermic reaction of isocyanate groups with amino groups. Sincedispersions having a solids content of about 10% by weight are generallyused for producing polyurethane resins, it is possible to mix theconcentrated dispersions with high proportions by weight of thosehydroxyl containing alcohols, e.g. polyesters, which might partiallyreact with water or amino compounds, e.g. hydrolysis or aminolysis, atthe temperatures at which preparation of the dispersion is carried out.Thus, for example, a 10% (20%) dispersion in which the proportion byweight of polyether to polyester is 1:8 (1:3) and which has a viscosityonly slightly higher than that of the pure polyester can be obtainedfrom a 50% polyhydrazodicarbonamide dispersion in polyether by stirringfour times (1.5 times) its quantity of polyester into it (see Examples).

Compared with the possible analogous method of preparation of non-ionicdispersions, the process according to the invention, preferably carriedout using chain lengthening agents containing salt groups, issurprisingly found to be generally simpler in practice to carry outbecause the water content in the reaction mixture is not very important.Satisfactory products are obtained both with relatively large and withrelatively small quantities of water whereas, when preparing dispersionsof non-ionogenic products, it is generally necessary to keep thequantity of water within a more restricted range. The ions presentevidently increase the compatibility between polyol and water by virtueof their hydrophilic character, but they also increase the compatibilitybetween these components and the dispersed ionic solid matter.

The use of higher molecular weight hydroxyl polyethers as dispersingagents in the process according to the invention opens up thepossibility, as already mentioned above, of a highly economic andvariable method of commercial production carried out under mildconditions to produce dispersions having a high solids concentrationwhich may, if desired, be used as master batches. The use of polyethershas, however, yet another important advantage: The large scalecommercial production of polyethers in most cases leads to the formationof intermediate stages of aqueous crude polyethers having a watercontent of from 8 to 12% and containing from 0.3 to 1% by weight ofalkali metal sulphates in solution and, in addition, from 1 to 3% byweight of toluene in suspension. Such a crude polyether suspension isnormally distilled under reduced pressure to reduce the water andtoluene to a residue of from 0.4 to 1% by weight. The alkali metalsulphates are thereby precipitated and can be removed by means of spongefilters.

The polyether, now free from sulphates and containing from 0.5 to 1% byweight of water, is substantially freed from its residual water contentby thin layer evaporation so that the purified commercial polyethercontains less than 0.5% by weight of water. For the process according tothe invention, however, it is not necessary to use a highly purified,practically anhydrous polyether. The preliminary crude polyether stagesare satisfactory for the process, either the substance obtained beforethin layer evaporation or, what is particularly advantageous, theso-called crude polyether suspension (containing about 10% of water,alkali metal sulphate and toluene). In the process according to theinvention, the water, toluene and sulphate are removed by distillationand filtration after termination of the isocyanate polyadditionreaction.

According to another possible variation of the present invention,polyisocyanate polyaddition products dispersed in the polyhydroxylcompounds are subsequently cross-linked with formaldehyde in knownmanner in the presence of catalytic quantities of acids or bases. It issurprisingly found that cross-linked dispersions of this kind are alsofinely disperse and stable in storage.

The dispersions prepared by the process according to the invention canbe used as "modified" lower or higher molecular weight polyhydroxylcompounds in known manner in reactions with polyisocyanates of the kindmentioned above, to which unmodified polyhydroxyl compounds orpolyamines, hydrazines or hydrazides of the kind mentioned above may beadded as chain lengthening agents. Blowing agents, catalysts and otheradditives may also be added to produce polyurethane resins with improvedmechanical properties. Examples of the products which may be producedinclude foams, elastomers, homogeneous and porous coatings, lacquers andthermoplastic polyurethanes. In addition, the products of the processmay be used as they are or after conversion to "modified" prepolymers byreaction with a polyisocyanate excess for producing aqueous polyurethanedispersions by known methods.

One factor which is of major importance in determining the improvementin properties in the resulting polyurethane resins, particularly theimprovement in compression resistance and tensile strength, is theparticle size of the dispersed polyaddition products. Thus, for example,when using polyether dispersions as starting materials for theproduction of polyurethane foams, the diameter of the particles offiller must be substantially below the dimensions of the cell walls (20to 50 μm). In polyurethane coatings, the particles must be small enoughto ensure that even very thin coatings can be applied evenly and have asmooth surface.

The process according to the invention advantageously gives rise todispersions having particles sizes of from 0.01 to 5 μm, preferably 0.1to 1 μm, which satisfy commercial requirements.

One particularly preferred purpose for which the ionic dispersionsaccording to the invention are used is the production of foams whichcontain ionic groups, (i.e. foams which have been rendered hydrophilic).One of the characteristics of such hydrophilic foams, for example, isthat they are wetted more easily and are capable, depending on theirhydrophilic character, of absorbing larger quantities of water thanconventional products. The foams may also be used, for example, as ionicexchangers.

To produce such foams, the hydroxyl groups of the dispersing agent,which may also contain reactive groups still present in the dispersedpolyurethane particles, are reacted with the isocyanates described abovein the presence of blowing agents, for example in the presence of thewater still left in the dispersions from the process used for preparingthem.

According to one special variation of this process, aqueous polymerlatices may be added to the reaction mixture before foaming for exampleby analogy to the process described in German Offenlegungsschrift No.2,014,385 and U.S. Pat. No. 2,993,013. This modification can be used forfurther modifying the properties of the hydrophilic foams.

The foams with ionic groups have a substantially higher conductivitythan conventional non-ionic products. They are very suitable for theknown methods of high frequency welding techniques. The products alsohave a distinctly increased capacity for dye absorption.

If desired, other compounds which are reactive with isocyanates as wellas catalysts, organic blowing agents, fillers and additives, may also beused.

Suitable organic blowing agents include e.g. acetone; ethyl acetate;halogenated alkanes such as methylene chloride, chloroform, ethylidenechloride, vinylidene chloride, monofluorotrichloromethane,chlorodifluoromethane and dichlorodifluoromethane; butane, hexane,heptane and diethylether. The action of a blowing agent can also beobtained by the addition of compounds which decompose at temperaturesabove room temperature to liberate gases such as nitrogen, e.g. azocompounds such as azoisobutyric acid nitrile. Other examples of blowingagents and details concerning the use of blowing agents may be found inKunstoff Handbuch, Volume VII, published by Vieweg and Hochtlen,Carl-Hanser-Verlag, Munich 1966, e.g. on pages 108 and 109, 453-455 and507-510.

Catalyst may in many cases be used. These include known catalysts suchas tertiary amines, e.g., triethylamine; tributylamine;N-methylmorpholine; N-ethylmorpholine; N-cocomorpholine;N,N,N',N'-tetramethylethylene diamine; 1,4-diazabicyclo-(2,2,2)-octane;N-methyl-N'-dimethyl-aminoethylpiperazine; N,N-dimethylbenzylamine;bis-(N,N-diethylaminoethyl) adipate; N,N-diethylbenzylamine;pentamethyldiethylenetriamine; N,N-dimethylcyclohexylamine;N,N,N',N'-tetramethyl-1,3-butanediamine;N,N-dimethyl-β-phenylethylamine; 1,2-dimethylimidazole; and2-methylimidazole. The known Mannich bases obtained from secondaryamines such as dimethylamine and aldehydes, preferably formaldehyde, orketones such as acetone, methyl ethyl ketone, cyclohexanone and phenolssuch as phenol itself, nonylphenol or bisphenol may also be used ascatalyst.

Suitable catalyst in the form of tertiary amines having hydrogen atomswhich are reactive with isocyanate groups include e.g. triethanolamine,triisopropanolamine, N-methyldiethanolamine, N-ethyl-diethanolamine,N,N-dimethylethanolamine and their reaction products with alkyleneoxides such as propylene oxide and/or ethylene oxide.

Silaamines having carbon-silicon bonds may also be used as catalysts,for example those described in German Pat. No. 1,229,290 and U.S. Pat.No. 3,620,984, e.g. 2,2,4-trimethyl-2-silamorpholine and1,3-diethylaminomethyl-tetramethyl-disiloxane.

Basic nitrogen compounds such as tetraalkylammonium hydroxides, alkalimetal hydroxides such as sodium hydroxide, alkali metal phenolates suchas sodium phenolate and alkali metal alcoholates such as sodiummethylate may also be used as catalysts. Hexahydrotriazines are alsosuitable catalysts.

Organic metal compounds may also be used as catalysts in particularorganic tin compounds.

The organic tin compounds used are preferably tin (II) salts ofcarboxylic acids such as tin(II) acetate, tin(II) octoate, tin(II) ethylhexoate and tin(II) laurate, and tin(IV) compounds such as dibutyl tinoxide, dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tindilaurate, dibutyl tin maleate or dioctyl tin diacetate. Any of theabove mentioned catalysts may, of course be used as mixtures.

Other representatives of catalysts which may be used and detailsconcerning the action of the catalyst may be found inKunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen,Carl-Hanser-Verlag, Munich 1966, e.g. on pages 96 to 102.

The catalysts are generally used in a quantity of between about 0.001and 10% by weight.

Surface-active additives such as emulsifiers and foam stabilizers mayalso be used when producing polyurethane foams. Suitable emulsifiersinclude e.g. the sodium salts of ricinoleic sulphonates or salts offatty acids with amines such as oleic acid diethylamine or stearic aciddiethanolamine. Alkali metal or ammonium salts of sulphonic acids suchas dodecylbenzenesulphonic acid or dinaphthylmethane disulphonic acid orof fatty acids such as ricinoleic acid or of polymeric fatty acids mayalso be used as surface active additives.

Suitable foam stabilizers are, particularly, the polyether siloxanes,especially those which are water soluble. These compounds generally havea polydimethylsiloxane group attached to a copolymer of ethylene oxideand propylene oxide. Foam stabilizers of this kind have been describedfor example, in U.S. Pat. Nos. 2,834,748; 2,917,480 and 3,629,308.

Other additives which may be used in the production of polyurethaneresins include reaction retarders, e.g. substances which are acid inreaction such as hydrochloric acid or organic acid halides; cellregulators known per se such as paraffins, fatty alcohols ordimethylpolysiloxanes; pigments; dyes; flame retarding agents known perse such as trischloroethylphosphate, tricresyl phosphate, ammoniumphosphate and polyphosphate; stabilizers against ageing and weathering;plasticizers; fungistatic and bacteriostatic substances; and fillerssuch as barium sulphate, kieselguhr, carbon black or whiting.

Other examples of surface active additives, foam stabilizers, cellregulators, reaction retarders, stabilizers, flame retarding substances,plasticizers, dyes, fillers and fungistatic and bacteriostaticsubstances which may also be used when producing polyurethane resins anddetails concerning their use and mode of action may be found inKunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen,Carl-Hanser-Verlag, Munich 1966, e.g. on pages 103 to 113.

The components used for production of the foams are reacted by the knownone-shot prepolymer or semiprepolymer process, in many cases usingmechanical devices such as those described in U.S. Pat. No. 2,764,565.Details concerning processing apparatus which may be used may be foundin Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen,Carl-Hanser-Verlag, Munich 1966, e.g. on pages 121 to 305.

The foaming reaction for producing the foams is often carried out insidemolds. The reaction mixture is introduced into a mold made of a metalsuch as aluminum or a synthetic product such as epoxide resin and isfoamed up inside the mold to produce the shaped product. Foaming insidemolds may be carried out either to produce articles having a cellularstructure on their surface or to produce articles having a compact skinand cellular center. One or other effect can be achieved by eitherintroducing just sufficient reaction mixture into the mold to fill themold after foaming or introducing a larger quantity of reaction mixture.The latter method is known as "overcharging", a procedure which has beendescribed, for example, in U.S. Pat. Nos. 3,178,490 and 3,182,104.

The process of foaming in molds is frequently carried out using known"external mold release agents" such as silicone oils but so-called"internal mold release agents" may also be used, optionally in admixturewith external mold release agents, e.g. as disclosed in GermanOffenlegungsschriften Nos. 2,121,670 and 2,307,589.

Cold setting foams can also be produced as described in British Pat. No.1,162,517 and German Offenlegungsschrift No. 2,153,086.

Foams may, of course, also be produced by the process of block foamingor by the known laminator process.

The following Examples serve to explain the process according to theinvention. The figures given represent parts by weight of percentages byweight unless otherwise indicated.

EXAMPLE 1 20% Anionic polyurea dispersion in trifunctional polyether

Index (NCO/NH·100)=100

Anion equivalent quantity=0.275/100 g of solid matter

Reaction mixture:

80.0 parts by weight of a polyether of propylene oxide and ethyleneoxide started on trimethylol propane and having a hydroxyl number of 34and containing about 80% of primary hydroxyl groups (hereinafterreferred to as "polyether I") as dispersing agent;

9.6 parts by weight of tolylene diisocyanate (isomeric mixture2,4:2,6=80:20) hereinafter referred to as "T 80";

10.4 parts by weight of aliphatic diamine sulphonate H₂ N--CH₂ --CH₂--NH--CH₂ --CH₂ --SO₃.sup.⊖ Na.sup.⊕, hereinafter referred to as AASsalt (used as 45% aqueous solution); and a total of

11% by weight of water, based on the quantity of reaction mixtureincluding water (=15.3%, based on dispersing agent; 61.3% based on solidmatter; 12.3% based on anhydrous dispersion).

PREPARATION OF THE DISPERSION

A mixture of dispersing agent and aqueous diamine sulphonate solution isheated to 45° C. in a stirrer vessel equipped with reflux condenser. Theisocyanate is then rapidly stirred in so that the heat released by theexothermic reaction raises the temperature to 80° to 100° C. Stirring iscontinued for 20 to 30 minutes after all the isocyanate has been added.Water is finally distilled off at reduced pressure. The resulting veryfinely divided, stable 20% dispersion containing a residue of 0.6% ofwater has a viscosity of 2400 cP/25° C.

EXAMPLE 2 12% Anionic polyurea dispersion in trifunctional polyether

Index=128

Anion equivalent quantity=0.242/100 g of solid matter.

Reaction mixture:

88.0 parts by weight of polyether I;

6.5 parts by weight of diisocyanate T 80;

5.5 parts by weight of AAS salt;

6.1% by weight of water, based on reaction mixture including water (7.4%based on dispersing agent; 54.2% based on solid matter; 6.5% based onanhydrous dispersion).

The method is similar to that described in Example 1. The resulting,finely divided dispersion which has a solids content of 12% and containsa residue of 0.2% of water has a viscosity of 2400 cP/25° C.

EXAMPLE 3 22.3% Anionic polyurea dispersion in trifunctional polyether

Index=100

Anion equivalent quantity=0.27/100 g of solid matter.

Reaction mixture:

77.7 parts by weight of polyether I;

7.7 parts by weight of diisocyanate T 80;

3.3 parts by weight of phenyl isocyanate;

11.3 parts by weight of AAS salt;

11.6% by weight of water, based on reaction mixture including water(=17% based on dispersing agent, 59.3% based on solid matter, 13.2%based on anhydrous end product).

The procedure is similar to that of Example 1. A 22.3% dispersioncontaining a residue of 0.4% of water and having a viscosity of 2850cP/25° C. is obtained.

EXAMPLE 4 14.2% Polyurea-polyhydrazodicarbonamide dispersion intrifunctional polyether

Index=100

Anion equivalent quantity=0.043/100 g solid matter

Reaction mixture;

85.8 parts by weight of polyether I;

11.2 parts by weight of diisocyanate T 80;

1.1 part by weight of AAS salt,

1.9 parts by weight of hydrazine (in the form of 99% hydrazine hydrate;added together with the AAS salt solution), and a total of

2.3% by weight of water, based on the reaction mixture including water(=2.8% based on dispersing agent, 16.8% based on solid matter, 2.4%based on anhydrous dispersion).

PREPARATION OF THE DISPERSION

The 45% aqueous AAS salt solution and hydrazine hydrate are mixed withthe dispersing agent in a stirrer vessel and the reaction is thenstarted by the addition of diisocyanate at room temperature. Thereaction temperature rises to 60°-80° C. After 60 minutes, water isdistilled off at reduced pressure.

The resulting stable 14.2% dispersion which still contains a residue of0.3% of water has a viscosity of 6300 cP/25° C. After dilution to 10%with a further quantity of polyether I, it has a viscosity of 3400cP/25° C.

COMPARISON EXPERIMENT

When no aqueous AAS salt solution is used, i.e. when hydrazine hydrateis used alone under otherwise the same reaction conditions and at thesame index, a non-ionic 14% paste having a viscosity of 125,000 cP/25°C. is obtained

EXAMPLE 5 39.1% Polyurea polyhydrazo-dicarbonamide dispersion intrifunctional polyether

Index=100

Anion equivalent content--0.03/100 g of solid matter

Reaction Mixture:

60.9 parts by weight of polyether I,

31.5 parts by weight of diisocyanate T 80.

2.1 parts by weight of AAS salt,

5.5 parts by weight of hydrazine (as 99% hydrate),

23.8% by weight of water based on reaction mixture including water(51.5% based on dispersing agent, 80% based on solid matter, 31.3% basedon anhydrous dispersion).

PREPARATION OF THE DISPERSION

The reaction vessel used is a stirrer vessel with highly efficientreflux condenser and an inlet tube with non-return valve in the lowerthird of the reaction vessel. The dispersing agent, heated to 80° C., ismixed with the diluted aqueous solution of hydrazine hydrate and AASsalt. The diisocyanate is then forced in so rapidly at the sametemperature, with stirring that polyaddition proceeds under vigorousreflux. Distillation of water is started after 10 minutes at reducedpressure. The temperature rises to 110° C. towards the end of thereaction, and the practically anhydrous dispersion obtained is runthrough a 100 μm sieve. The very finely divided and stable 39.1%dispersion obtained in this way has a viscosity of 11,500 cP/25° C. Whendiluted to 20% by weight or 10% by weight with polyether I, thedispersion has a viscosity of 2100 cP or 1310 cP/25° C. If, on the otherhand, the water is distilled off only after 2 days, difficulties arisewhen attempts are made to heat the highly viscous paste, which contains23.8% of water, when it has cooled to room temperature. Furthermore, theviscosity of the anhydrous dispersion is between 2.5 and 4 times higher,depending on its solid content, than that found after directdistillation.

EXAMPLE 6

The 39.1% dispersion described in Example 5 is vigorously mixed at 30°to 60° C. with a polyester (hydroxyl number 56, acid number 1, viscosity21,400 cP/25° C.) prepared from trimethylolpropane, diethylene glycoland adipic acid. It is surprisingly found that the following stabledispersions are obtained:

(a) a dispersion having a solids content of 20% (ratio by weight ofpolyester to polyether=5:3), has a viscosity of 17,800 cP/25° C.;

(b) a dispersion having a solids content of 10% (ratio by weight ofpolyester to polyether=5:1) has a viscosity of 9600 cP/25° C.

If, for comparison, the unmodified polyester and polyether are mixed inthe given ratios by weight, phase separation occurs within a short time.

EXAMPLE 7 Tetrahydroxyalkyl-functional polyurea dispersion intrifunctional polyether

Index 1: (NCO/NH·100)=100

Index 2: (NCO/(NH+OH)·100)=91

Anion equivalent content=0.028/100 g solid matter.

Reaction mixture:

60.0 parts by weight of polyether I but in the form of the crude ethersuspension containing 12% by weight of water and 0.7% by weight ofalkali metal sulphate;

31.0 parts by weight of diisocyanate T 80.

2.2 parts by weight of AAS salt,

1.8 parts by weight of diethanolamine,

5.0 parts by weight of hydrazine hydrate (in the form of the 99% hydratediluted with water) and a total of

20% by weight of water, based on the reaction mixture including water(41.6% based on dispersing agent, 62.5% based on solid matter, 25% basedon anhydrous dispersion).

The procedure employed for preparing the dispersion is similar to thatof Example 5. The resulting, very finely divided, dispersion has aviscosity of 5290 (or 1750 or 1050) cP/25° C. at a concentration of 40%(or 20% or 10%).

EXAMPLE 7a

When the 40% dispersion in polyether obtained according to Example 7 isdiluted with the same polyester as in Example 6, stable polyureadispersions are obtained (polyether:polyester=3:5 or 1:5) which atconcentrations of 20% and 10% have a viscosity of 17,200 cP/25° C. or21,000 cP/25° C.

EXAMPLE 7b

When Example 7 is repeated but the quantity of polyether in the reactionmixture is reduced so that the concentration of solid matter is 50% and,if a total of 20% by weight of water is used, based on the quantity ofreaction mixture (50% based on dispersing agent or solid matter, 25%based on anhydrous dispersion), a very finely divided, stable dispersionhaving a viscosity of 6150 cP/25° C. is obtained. When this is dilutedwith pure dispersing agent to a solid content of 40%, 20% or 10%, theresulting dispersions have viscosities of 3400, 1480 and 1030 cP/25° C.

EXAMPLE 7c

If Example 7 is repeated but the quantity of polyether is modified sothat the solid content of the resulting dispersion is 60% and if a totalof 20% by weight of water is added, based on the quantity of reactionmixture (62.5% based on dispersing agent, 41.6% based on solid matter,25% based on anhydrous dispersion), a finely divided, stable dispersionhaving a viscosity of 28,700 cP/25° C. is obtained. When the dispersionis diluted to a solid content of 40%, 20% or 10%, the resultingviscosities are 3800, 1550 and 1080 cP/25° C.

EXAMPLE 8 17.8% polyurea-polyhydrazo-dicarbonamide dispersion intrifunctional polyether

Index=100

Carboxylate-ion equivalent quantity=0.04/100 g of solid matter.

Reaction mixture:

82.2 parts by weight of a polyethylene oxide, started ontrimethylolpropane (OH number 550, hereinafter referred to as polyetherII);

15.2 parts by weight of tolylene diisocyanate (mixture of isomers2,4:2,6=65:35);

1.4 parts by weight of hydrazine (in the form of 99% hydrate dilutedwith water);

1.2 parts by weight of the diaminocarboxylate of the formula

    H.sub.2 N--CH.sub.2 --CH.sub.2 --NH--CH.sub.2 --CH.sub.2 --COO.sup.⊖ Li.sup.⊕

and a total of

10% by weight of water, based on the quantity of reaction mixtureincluding water (13.8% based on dispersing agent, 59.5% based on solidmatter, 11.2% based on anhydrous dispersion).

A finely divided 17.8% dispersion having a viscosity of 3200 cP/25° C.is obtained under the reaction conditions indicated in Example 5. Whenthe dispersion is diluted to 10% using pure dispersing agent, theresulting viscosity is 2100 cP/25° C.

EXAMPLE 9 14.2% Polyurea-polyhydrazodicarbonamide dispersion in linearpolyether

Index=100

Sulphonate-ion equivalent content=0.04/100 g of solid matter.

Reaction Mixture:

85.8 parts by weight of linear polypropylene glycol having secondaryhydroxyl groups (hydroxyl number 56, hereinafter referred to aspolyether III);

10.5 parts by weight of diisocyanate T 80,

1.8 parts by weight of hydrazine (used as 99% hydrate),

1.9 parts by weight of diaminosulphonate of the formula ##STR4##

10% by weight of water, based on the quantity of reaction mixtureincluding water (13.8% based on dispersing agent, 59.5% based on solidmatter, 11.2% based on anhydrous dispersion).

When the general method of procedure described in Example 1 is employed;a stable 14.2% dispersion having a viscosity of 3,800 cP/25° C. isobtained. When this is diluted to 10% with pure dispersing agent, thediluted dispersion has a viscosity of 2250 cP/25° C.

COMPARISON EXAMPLE

When only 1% by weight of water instead of 10% is used in the reactionmixture under otherwise identical conditions, a paste having a viscosityof 280,000 cP/25° C. is obtained.

EXAMPLE 9a

If a 14% polyether dispersion is prepared in a manner analogous toExample 9 using a mixture of 5.22 parts by weight of diisocyanate T 80and 7.5 parts by weight of 4,4'-diphenylmethane diisocyanate, a stabledispersion is obtained having a viscosity of 4500 cP/25° C. whenanhydrous at a solid content of 14% and a viscosity of 2550 cP/25° C. ata solid content of 10%.

EXAMPLE 10 20% Cationic polyurethane dispersion in linear polyether

Index=100

Cation equivalent quantity=0.34/100 g of solid matter.

Reaction Mixture:

80.0 parts by weight of polyether III;

11.8 parts by weight of diisocyanate T 80;

8.2 parts by weight of N-methyldiethanolamine,

7% by weight of water, based on the total quantity of reaction mixture.

METHOD OF PREPARATION

Polyether, water and N-methyl diethanolamine are mixed in a vesselequipped with stirrer. The diisocyanate is then added slowly withcooling so that the reaction temperature does not rise above 50° C. Thewater is distilled off at reduced pressure 60 minutes after all thediisocyanate has been added. Towards the end of distillation, thetemperature is gradually raised to 90° C. A dispersion having aviscosity of 2110 cP/25° C. is obtained. This dispersion is quaternizedin a second stage:

An equivalent quantity (based on tertiary nitrogen) of dimethylsulphatediluted with 4 times its quantity by weight of pure dispersing agent isgradually introduced into the dispersion with vigorous stirring. Thereaction mixture is kept at 60° to 70° C. for 30 minutes with stirringto complete the reaction. The finely divided cationic dispersionobtained has a viscosity of 1380 cP/25° C. at a solids content of 20%.

EXAMPLE 11 9.5% Cationic polyurea-polyhydrazodicarbonamide dispersion intrifunctional polyether

Index=100

Cation equivalent content=0.04/100 g of solid matter.

Reaction Mixture:

90.5 parts by weight of polyether I,

7.3 parts by weight of diisocyanate T 80,

1.2 parts by weight of hydrazine (added in the form of 99% hydrazinehydrate),

0.6 parts by weight of triamine of the formula ##STR5##

0.4 parts by weight of dimethylsulphate,

10% by weight of water, based on the quantity of reaction mixture(practically completely removed by distillation before quanternizationis carried out).

The method employed in the first stage (preparation of dispersion) isanalogous to that of Example 1 and in the second stage (quaternization)analogous to that of Example 10. A stable cationic 9.5% dispersionhaving a viscosity of 2350 cP/25° C. is obtained.

EXAMPLE 12 4% polyurea dispersion in copolyester

Index=50

Ion equivalent content=0.364/100 g of solid matter.

Reaction Mixture:

96 parts by weight of copolyester of 1,6-hexanediol, neopentyl glycoland adipic acid (OH number 63, acid number 1.5),

1.2 parts by weight of 1,6-hexamethylenediisocyanate,

2.8 parts by weight of AAS salt,

3.1% by weight of water, based on the quantity of reaction mixture (3.4%based on dispersing agent, 81.3% based on solid matter, 3.2% based onend product).

The method is similar to that of Example 1. An anhydrous polyesterdispersion is obtained which has a softening point 25° C. lower thanthat of the pure polyester.

EXAMPLE 13 33.7% polyurea dispersion in tetraethylene glycol

Reaction Mixture:

66.3 parts by weight of tetraethyleneglycol,

16.6 parts by weight of diisocyanate T 80,

17.1 parts by weight of AAS (as aqeuous solution) and a total of

20% by weight of water, based on the total quantity of reaction mixture(38% based on dispersing agent 74.6% based on solid matter, 25% based onanhydrous dispersion).

The method is similar to that of Example 1. A stable, finely divideddispersion having a viscosity of 2950 cP/25° C. is obtained.

The following Examples illustrate the use of the ionic dispersionsaccording to the invention for producing soft foams and cold setting,highly elastic polyurethane foams or elastomers and aqueous polyurethanedispersions.

EXAMPLE 14

100 parts by weight of anionic polyhydrazodicarbonamidepolyetherdispersion from Example 5 adjusted to a solid content of 10%

2.7 parts by weight of water,

0.03 parts by weight of triethylamine,

0.2 parts by weight of 2-dimethylamino-ethanol

0.8 parts by weight of commercial polysiloxane stabilizer (OS 20 ofBayer AG) and

0.35 parts by weight of tin-(II) octoate are mixed together. The mixtureis vigorously stirred together with 33.4 parts by weight of tolylenediisocyanate (65% 2,4- and 35% 2,6- isomer) at room temperature.

A creamy reaction mixture forms within 7 seconds. It has a rise time of70 seconds and a gel time of 115 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density    according to DIN 53420                                                        41 kg/m.sup.3                                                Tensile strength according to DIN 53571                                                        160 kPa                                                      Elongation at break                                                                            according to DIN 53571                                                        195%                                                         Compression resistance                                                                         according to DIN 53577                                                        6.3KPa                                                       Indentation hardness                                                                           according to ASTM D 1564-71T:                                H-value at 25% deformation                                                                     302                                                          H-value at 65% deformation                                                                     597                                                          RH-value at 25% deformation                                                                    194                                                          (25% RH-value/25%                                                                              66%                                                          H-value × 100                                                           65% H-value/25% H-value                                                                        2.0                                                          ______________________________________                                    

The specific electric resistance of this foam according to DIN 52,482 is6.2×10¹² Ohm.cm whereas a comparable foam produced without a polyetherhaving ionic groups has a corresponding resistance of 2.1×10¹³ Ohm.cm.

EXAMPLE 15

100 parts by weight of the dispersion from Example 14,

5.5 parts by weight of water,

0.03 parts by weight of triethylenediamine,

0.3 parts by weight of 2-dimethylaminoethanol,

1.5 parts by weight of polysiloxane stabilizer (OS 20 of Bayer AG) and

0.35 parts by weight of tin-(II) octoate are mixed together. 59.8 partsby weight of tolylene diisocyanate (65% 2,4-isomer and 35% 2,6-isomer)are added to this mixture with vigorous stirring at room temperature. Acreamy reaction mixture is formed after 6 seconds. It has a rise time of78 seconds and a gel time of 124 seconds.

The foam obtained is found to have the following mechanical properties:

    ______________________________________                                        Gross density    according to DIN 53420                                                        22 kg/m.sup.3                                                Tensile Strength according to DIN 53571                                                        135 KPa                                                      Elongation at break                                                                            according to DIN 53571                                                        170%                                                         Compression resistance                                                                         according to DIN 53577                                                        3.8 KPa                                                      Indentation hardness                                                                           according to ASTM D 1564-71T                                 H-value at 25% deformation                                                                     128                                                          H-value at 65% deformation                                                                     260                                                          RH-value at 25% deformation                                                                    82                                                           (25% RH-value/25%                                                                              64%                                                          H-value) × 100                                                          65% H-value/25% H-value                                                                        2.0                                                          ______________________________________                                    

The following Examples demonstrate the manufacture of a cold setting,highly elastic polyurethane foam.

EXAMPLE 16

100 parts by weight of the dispersion used in Example 14,

3.0 parts by weight of water,

0.1 part by weight of triethylene diamine,

0.3 parts by weight of 2-dimethylamino-ethanol,

1.0 part by weight of a commercial polysiloxane polyether foamstabilizer manufactured by Goldschmidt (B 3207)

2.0 parts by weight of diethanolamine and

2.0 parts by weight of trichloroethyl phosphate are mixed together. 38.1parts by weight of tolylene diisocyanate (80% 2,4-isomer and 20%2,6-isomer) are added to this mixture at room temperature and mixed. Acreamy reaction mixture is formed after 7 seconds. It has a rise time of135 seconds and a gel time of 148 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density   according to DIN 53420                                                        36 kg/m.sup.3                                                 Tensile strength                                                                              according to DIN 53571                                                        95 KPa                                                        Elongation at break                                                                           according to DIN 53571                                                        150%                                                          Compression resistance                                                                        according to DIN 53577                                                        2.4 KPa                                                       Indentation hardness                                                                          according to ASTM D1564-71T:                                  H-value at 25% deformation                                                                    93                                                            H-value at 65% deformation                                                    RH-value at 25% deformation                                                                   76                                                            (25% RH-value/  82%                                                           H-value) × 100                                                          65% H-value/25% H-value                                                                       2.4                                                           ______________________________________                                    

EXAMPLE 17

100 parts by weight of the dispersion according to Example 14,

3.0 parts by weight of water,

0.06 parts by weight of triethylene diamine,

0.2 parts by weight of 2-dimethylaminoethanol,

1.0 part by weight of a commercial siloxane foam stabilizer manufacturedby Goldschmidt (B 3207),

2.0 parts by weight of diethanolamine and

2.0 parts by weight of trichloroethylphosphate are mixed together. 38.1parts by weight of tolylene diisocyanate (80% 2,4-isomer and 20%2,6-isomer) are added to the mixture at room temperature and thecomponents are vigorously mixed while air is added at an excess pressureof 0.5 atmospheres. A creamy reaction mixture forms after 8 seconds. Ithas a rise time of 145 seconds and a gel time of 163 seconds.

The foam obtained is found to have the following mechanical properties:

    ______________________________________                                        Gross density    according to DIN 53420                                                        41 kg/m.sup.3                                                Tensile strength according to DIN 53571                                                        130 KPa                                                      Elongation at break                                                                            according to DIN 53571                                                        95%                                                          Compression resistance                                                                         according to DIN 53577                                                        3.6 KPa                                                      Indentation hardness                                                                           according to ASTM D 1564-71T:                                H-value at 25% deformation                                                                     82                                                           H-value at 65% deformation                                                    RH-value at 25% deformation                                                                    68                                                           (25% RH-value/25%                                                                              85%                                                          H-value) × 100                                                          65% H-value/25% H-value                                                                        2.5                                                          ______________________________________                                    

EXAMPLE 18

100 parts by weight of the cationic dispersion of Example 11 adjusted toa solid content of 9.5%

2.7 parts by weight of water,

0.1 part by weight of triethylenediamine,

0.3 part by weight of 2-dimethylaminoethanol,

0.8 parts by weight of polysiloxane stabilizer (OS 15 of Bayer AG and

0.2 parts by weight of tin-(II) octoate are stirred together. 33.4 partsby weight of tolylene diisocyanate (80% 2,4-isomer and 20% 2,6-isomer)are added to this mixture at room temperature and the mixture isvigorously stirred. A creamy reaction mixture which has a rise time of240 seconds is formed after 15 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density   according to DIN 53420 10 kg/m.sup.3                          Tensile strength                                                                              according to DIN 53571 150 KPa                                Elongation at break                                                                           according to DIN 53571 160%                                   Compression resistance                                                                        according to DIN 53577 6.1 KPa                                Pressure deformation                                                          residue:                                                                      (22h at 70° C. 90%)                                                                    according to DIN 53572 9.9                                    ______________________________________                                    

EXAMPLE 19

100 parts by weight of the cationic dispersion used in Example 18,

3.0 parts by weight of water,

0.1 part by weight of triethylenediamine,

0.3 parts by weight of 2-dimethylaminoethanol,

1.0 parts by weight of a commercial polyether polysiloxane foamstabilizer of Goldschmidt (B 3207),

2.0 parts by weight of diethanolamine and

2.0 parts by weight of trichloroethylphosphate are mixed together. 37.4parts by weight of tolylene diisocyanate (80% 2,4-isomer and 20%2,6-isomer) are vigorously stirred into the mixture at room temperature.A creamy reaction mixture which has a rise time of 118 seconds isobtained after 10 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density   according to DIN 53420 31 kg/m.sup.3                          Tensile strength                                                                              according to DIN 53571 90 KPa                                 Elongation at break                                                                           according to DIN 53571 100%                                   Compression resistance                                                                        according to DIN 53577 3.7 KPa                                Pressure deformation residue                                                  (22h at 70° C. 90%)                                                                    according to DIN 53572 6.4                                    ______________________________________                                    

EXAMPLE 20 Preparation of a 40% aqueous polyurethane dispersion Theanionic 4% polyurea dispersion in a polyester obtained according toExample 12 is converted into a polyisocyanate prepolymer by reactionwith excess 1,6-hexamethylene diisocyanate (index=190) at 80° to 120° C.The prepolymer is cooled to 50°-60° C. and an aqueous 1,2-propylenediamine solution (index=120) containing 10% by weight acetone (based onthe prepolymer) is rapidly added. The small proportion of solventpresent is subsequently distilled off. The resulting stable aqueous 40%dispersion has a viscosity of 850 cP at 25° C. and can be used, forexample, for coating textiles. COMPARISON EXPERIMENT

When preparation of the isocyanate prepolymer is carried out directly inthe presence of the AAS salt, normally present in the form of a 45%aqueous solution, gelling occurs within 10 to 20 minutes. When employingthe conventional procedure, it is therefore necessary first to prepare anon-ionic prepolymer and then to dissolve this in about twice itsquantity of acetone, based on the prepolymer (i.e. about 20 times thequantity of solvent used in Example 20) before the water and diamine maybe added. Finally, all the acetone must be distilled off.

EXAMPLE 21

100 parts by weight of the polyurea dispersion (dispersed inpolyester:polyether=5:1) according to Example 7a, adjusted to a solidcontent of 10%,

4.0 parts by weight of water,

0.6 parts by weight of dimethylbenzylamine;

0.1 part by weight of tin-(II) octoate,

2.0 parts by weight of a commercial polysiloxane foam stabilizer (OS 25of Bayer AG) are mixed together. The mixture is vigorously stirredtogether with 22.2 parts by weight of diisocyanate T 80 at roomtemperature. A creamy reaction mixture forms after 10 seconds. It has arise time of 65 seconds and a gel time of 125 seconds. In contrast tothe usual pure polyester foams, the foam obtained has open cells and,owing to its uniform, very fine cell structure it may be used e.g. asfilter material. If the example is repeated using a mixture ofunmodified pure polyester and polyether in the same proportions, an opencell foam is again obtained but it has substantially larger cells.

The mixture of pure polyester and polyether separates within a shorttime into two phases when left to stand at room temperature.

EXAMPLE 22 Preparation of a homogeneous polyether-polyurethane elastomer

The 50% polyether dispersion obtained according to Example 7B is reactedwith excess 4,4'-diphenylmethane diisocyanate at 100° to 120° C. toproduce an isocyanate prepolymer containing 2.3% by weight of freeisocyanate groups. 1,4-butanediol (index=104) is stirred into theprepolymer at the same temperature. The highly viscous melt is pouredout onto a surface (metal or glass) within 10 to 15 minutes and drawnout to a film of 250 μm using a doctor knife. The film is then heated at130° C., cooled and stripped from its substrate. The tensile strength ofthe film is 212 Kp/cm², its elongation at break 180% and its Shore Ahardness 77. The elastomer is insoluble even in hot dimethyl formamide.

COMPARISON EXPERIMENT

When the pure polyether is used instead of the dispersion but thereaction mixture is otherwise kept the same, stickypolyether-polyurethane film is obtained which has so little tensilestrength that it cannot be stripped from its substrate.

EXAMPLE 23

A mixture of

25 parts by weight of the 40% anionic dispersion according to Example 7,

75 parts by weight of a copolyether of 10% ethylene oxide and 90%propylene oxide started on trimethylolpropane (hydroxyl number 42),

8.4 parts by weight of a 64.6% aqueous polyvinyl chloride dispersion,

0.8 parts by weight of 2-dimethylaminoethanol,

0.3 parts by weight of polysiloxane foam stabilizer (OS 20 of Bayer AG)and

0.1 part by weight of tin-(II) octoate is vigorously stirred togetherwith 38.2 parts by weight of diisocyanate T 80.

A creamy reaction mixture forms after 14 seconds. It has a rise time of131 seconds.

The foam obtained is found to have the following mechanical properties:

    ______________________________________                                        Gross density  according to DIN 53420 24 kg/m.sup.3                           Tensile strength                                                                             according to DIN 53571 145 KPa                                 Elongation at break                                                                          according to DIN 53571 120%                                    Compression resistance                                                                       according to DIN 53547 4.2 KPa                                 ______________________________________                                    

EXAMPLE 24

A mixture of

100 parts by weight of the same polyether mixture as in Example 23,

7.5 parts by weight of a 33% aqueous ABS polymer dispersion

0.1 part by weight of triethylene diamine,

0.3 part by weight of 2-dimethylaminoethanol,

0.6 parts by weight of polysiloxane foam stabilizer (OS 20 of Bayer AG)and

0.2 parts by weight of tin-(II) octoate is vigorously stirred togetherwith 59.2 parts by weight of diisocyanate T 80.

A creamy reaction mixture forms after 15 seconds. It has a rise time of85 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density  according to DIN 53420 21 kg.m.sup.3                           Tensile strength                                                                             according to DIN 53571 90 KPa                                  Elongation at break                                                                          according to DIN 53571 100%                                    Compression resistance                                                                       according to DIN 53577 4.1 KPa                                 ______________________________________                                    

EXAMPLE 25

A mixture of

100 parts by weight of the polyether mixture used in Example 23,

5.0 parts by weight of a 40% aqueous copolymer dispersion of styrene andacrylonitrile,

0.8 parts by weight of 2-dimethylaminoethanol,

0.3 parts by weight of a polysiloxane foam stabilizer (OS 20 of BayerAG) and

0.1 parts by weight of tin-(II) octoate is vigorously stirred togetherwith 38.2 parts by weight of diisocyanate T 80.

A creamy reaction mixture which has a rise time of 145 seconds is formedafter 14 seconds.

The resulting foam is found to have the following mechanical properties:

    ______________________________________                                        Gross density  according to DIN 53420 34 kg/m.sup.3                           Tensile strength                                                                             according to DIN 53571 140 KPa                                 Elongation at break                                                                          according to DIN 53571 165%                                    Compression resistance                                                                       according to DIN 53577 4.6 KPa                                 ______________________________________                                    

EXAMPLE 26

Continuous method of carrying out the process of Example 1 in amultiphase reaction flow tube.

The reactants are stored in two storage vessels B1 and B2. Vessel B1contains a mixture of 8000 parts by weight of polyether I, 104 parts byweight of AAS salt and 127 parts by weight of water. Vessel B2 contains96 parts by weight of diisocyanate T 80. The rate of feed is 103.1 q perminute from B1 and 9.6 g per minute from B2, making a total of 112.7 gper minute.

METHOD

The mixture which has been heated to 95° C. in B1 and the diisocyanatewhich is kept at 20° C. in B2 are combined coaxially in a static mixermanufactured by Kenics (diameter 1/4 inch; 21 elements; volumeapproximately 3 ml) (residence time longer than 1.1 seconds) with theaid of a twin piston pump, and the mixture is delivered at a pressure of2 to 3 bar into a steel reaction tube having a length of about 6 m and adiameter of about 9 mm in which the temperature of the reaction mixtureis kept at 110°±5° C. by external heating or cooling. The reaction tubeopens into a decompression vessel in which the practically anhydrousdispersion is stirred at 80° C. and a pressure of 20 Torr during anaverage residence time of about 6 to 10 minutes. The decompressionvessel is connected to a distillation bridge and via a pump to a furthervessel which receives the end product. The resulting finely divideddispersion has a viscosity of 2050 cP at 25° C.

EXAMPLE 27

Example 7 is repeated, but using the internal salt of diaminodisulphonicacid of the following formula ##STR6## ("dibetaine") instead of the AASsalt indicated in the formulation. This dibetaine, however, must bedissolved in diethanolamine and hydrazine monohydrate (30% at 100° C. inwater). A very finely divided dispersion which has free sulphonic acidgroups is obtained.

At a concentration of 40%, it has a viscosity of 4450 cP at 25° C.

EXAMPLE 28 20% Anionic polyurea dispersion in Polyether I

Anion equivalent quantity=0.13/100 g of solids content.

FORMULATION

1562 parts by weight of Polyether I;

207.6 parts by weight of 46% aqueous AAS salt solution;

136 parts by weight of 25% aqueous ammonia solution

261 parts by weight of 2,4-tolylene diisocyanate (hereinafter referredto as T 100).

WATER CONTENT

11% by weight based on anhydrous dispersion.

REACTION CONDITIONS

The dispersing agent and aqueous solutions of the amino functionalcompounds are introduced into the reaction vessel as described inExample 1 and the diisocyanate is introduced into the liquid phase ofthe reaction mixture at such a rate that the temperature is raised from40° C. to 80° C. by the exothermic reaction.

The anhydrous 20% (10%) dispersion has a viscosity of 4900 (735) cP at25° C.

EXAMPLE 29 20% Anionic polyurea dispersion in polyether III

Anion equivalent quantity: 0.17/100 g of solid content.

FORMULATION

1164 parts by weight of polyether III;

204 parts by weight of 46.5% aqueous AAS salt solution;

34 parts by weight of 25% aqueous ammonia solution;

187.5 parts by weight of 4,4'-diphenylmethane diisocyanate (hereinafterreferred to as diisocyanate D44)

The total water content is 8.6% by weight, based on the anhydrousdispersion.

The method is the same as in Example 28 but in this case diisocyanate D44 heated to 80° C. is introduced into the reaction mixture kept at 25°to 30° C., and the temperature is adjusted by cooling so that it doesnot exceed 65° C.

The 20% (10%) anhydrous dispersion has a viscosity of 1820 (1150) cP at25° C.

EXAMPLE 30

An aqueous formalin solution (5% by weight formaldehyde based on thesolid content of the dispersion) and a catalytic quantity of toluenesulphonic acid are added to the dispersion obtained in Example 29,optionally before the water is removed from the dispersion bydistillation, and the temperature of the mixture is gradually raisedfrom 40° to 95° C. over a period of 60 to 90 minutes with stirring. Thewater is then distilled off at reduced pressure.

The resulting anionic polyurea dispersion which contains polymethyleneurea groups has a viscosity of 1890 cP at a concentration of 20%.

A polyurethane foam produced from this dispersion has a highercompression resistance than a foam produced from the unmodifieddispersion of Example 29.

EXAMPLE 31 20% Anionic polyurea dispersion in polyether III

Anion equivalent quantity: 0.18/100 g of solid content.

FORMULATION

1164 parts by weight of polyether III;

204 parts by weight of 46.5% aqueous AAS salt solution;

34 parts by weight of 25% aqueous ammonia solution;

43.5 parts by weight of diisocyanate T 100;

125 parts by weight of diisocyanate D 44

The total water content is 8.4% by weight, based on the anhydrousdispersion.

The method is analogous to that of Example 28 but diisocyanate T 100 isfirst added at 20° to 30° C., and thereafter diisocyanate D 44 (heatedto 80° C.) is added at 30° to 55° C.

The resulting finely divided, anhydrous, 20% dispersion has a viscosityof 1190 cP at 25° C.

What is claimed is:
 1. A process for the in situ preparation of a stabledispersion of polyisocyanate-polyaddition products in hydroxylcontaining compounds as dispersing agent which comprises reacting:(1)organic polyisocyanate with (2) at least one compound containing a groupselected from the group consisting of primary amino groups, secondaryamino groups, and primary hydroxyl groups in (3) as dispersing agent, analcohol selected from the group consisting of alcohols containing 2 to 8primary hydroxyl groups, alcohols containing 2 to 8 secondary hydroxylgroups, and mixtures thereof,with the proviso that compounds (3) havesecondary hydroxyl groups if compounds with primary hydroxyl groups areused as compounds (2), and further characterized in that at least one ofcomponent (1) or (2) has groups selected from the group consisting ofionic groups and groups capable of salt formation.
 2. The process ofclaim 1, wherein the reaction is carried out discontinuously in stirrervessels in the presence of from about 5 to about 50% by weight of water,based on the total quantity of reaction mixture.
 3. The process of claim2 further comprising the step of removing the water.
 4. The process ofclaim 1, wherein the polyaddition reaction is carried out continuouslyin continuous flow mixers.
 5. The process of claim 4 wherein the processis carried out in the presence of more than 1% by weight of water, basedon the total quantity of reaction mixture.
 6. The process of claim 5wherein the water is subsequently removed in known manner.
 7. Theprocess of claim 1, wherein the dispersing agents used are unpurifiedcrude polyethers containing water, solvents and alkali metal salts, suchas are obtained from the commercial production of polyethers.
 8. Theprocess of claim 1, wherein the compounds used as component (2) areselected from the groups consisting of polyamines, hydrazines, andhydrazides.
 9. The stable dispersion product of the process of claim 1.10. The process of claim 1, wherein said dispersing agent has amolecular weight of at least 62.